Microbiologist Awarded ERC Starting Grant for Carbon Dioxide Capture Research

In nature, there are already organisms that capture CO₂, such as plants and cyanobacteria. Some steps in that process are relatively slow and require a significant amount of energy. Therefore, Claassens aims to develop and test a more efficient mechanism using the bacterium E. coli.

Ten options for an improved Calvin cycle

Existing carbon capture processes rely on a series of biochemical reactions known as the Calvin cycle. In order to create an improved version of this cycle, scientists have studied 5,000 enzyme reactions found in nature. They attempted to identify which ones work well together. “Determining and refining such biochemical reactions is surprisingly challenging to do with a computer,” says Claassens. Therefore, researchers use their biochemical expertise to manually outline the enzyme reactions and calculate their energy requirements. Over the past fifteen years, researchers both within and outside Wageningen have designed dozens of biochemical pathways that—in theory—capture CO2, similar to the Calvin cycle. “We are now going to test whether these pathways actually work in living organisms,” Claassens explains.

In the coming years, Claassens and his team will focus on testing these pathways. “We don’t yet know how fast they are or whether they work better than the Calvin cycle,” Claassens notes. Therefore, the team will measure the speed of key enzymes within the designed pathways, not in a test tube as is typically done, but within a bacterial cell. This approach provides a more accurate picture of enzyme activity and also reveals any side effects of the enzyme reactions on the cell. Claassens hopes to eliminate most of the biochemical pathways from the candidate list, allowing him and his team to fully integrate one promising pathway into the bacterium.

Food and biofuel

In the future, this engineered bacterium could provide us with a variety of useful substances. The bacterium would convert CO₂ into a universal building block, which could then be developed into food, chemicals, or biofuels. “However, this is not the goal of the current project,” Claassens emphasises. “First, we need to identify the fastest route to capture CO₂ and determine whether we can successfully engineer this pathway into bacteria.”

Claassens sees the grant as a unique opportunity for himself and his team. “The ERC Starting Grant gives researchers the chance to pursue what they truly believe in,” he says. Over the next few years, he will work with a postdoctoral researcher and two PhD candidates to further advance the research. The grant also holds long-term benefits, he thinks. “Once you receive a personal grant, people take you seriously as a researcher, and this increases your chances of securing future funding”, Claassens says. “But this aspect of the system can sometimes feel somewhat unjust.”

ERC Starting Grant

The ERC Starting Grants are part of the EU’s Horizon Europe programme and support groundbreaking research across various fields, from medicine and physics to social sciences and humanities. These grants help early-career researchers establish their own projects, form their teams, and pursue their most innovative ideas.